The present disclosure relates to an air conditioner and a method for controlling the same.
Generally, a multi-type air conditioner is an apparatus in which a plurality of indoor units are connected to one outdoor unit, and also a plurality of pipes are connected to the outdoor unit to supply a refrigerant into each of the indoor units, thereby air-conditioning an indoor space. The multi-type air conditioner has an advantage in which an area of the outdoor unit can be reduced when compared to that of the prior air conditioner.
FIG. 1 is a schematic view of a multi-type air conditioner according to a related art. Referring to FIG. 1, a multi-type air conditioner 100 according to a related art includes a plurality of indoor units 110, an outdoor heat exchanger 120, an overcooling heat exchanger 130, a compressor 140, a gas/liquid separator 150.
In the multi-type air conditioner 100 according to the related art, when the air conditioner 100 is operated in a cooling mode, a refrigerant discharged from the compressor 140 passes through a 4-way valve and is condensed in the outdoor heat exchanger 120 (e.g., a condenser). Then, the refrigerant is discharged from the outdoor heat exchanger 120 in a high-temperature high-pressure liquid state.
Thereafter, the refrigerant is decreased in temperature while passing through the overcooling heat exchanger 130 and flows into each of the indoor units 110. Then, the refrigerant is phase-changed into a two-phase refrigerant while passing through an electric expansion valve (EEV) of each of the indoor units 110. Also, the refrigerant is heated by heat-exchanging with indoor air while passing through the indoor units 110 (e.g., evaporator), and then flows into the outdoor heat exchanger 120. Thereafter, the refrigerant flows into the compressor 140 via the 4-way valve and the gas/liquid separator 150.
On the other hand, when the air conditioner is operated in a heating mode, the indoor units 110 serve as condensers and the outdoor heat exchanger 120 serves as an evaporator. Thus, the refrigerant may flow in a direction opposite to the flow direction in case where the air conditioner is operated in the cooling mode.
However, in the multi-type air conditioner according to the related art, when the air conditioner is partially operated in the cooling mode, a portion of the indoor units 110 is stopped. Also, a refrigerant having a low pressure gaseous state may exist in the stopped indoor unit 110. Here, when the refrigerant is sealed in consideration of the number of operational indoor units 110, the refrigerant within nonoperational indoor units 110 is moved into the outdoor heat exchanger 120. Thus, the amount of refrigerant within a system may be varied. As a result, a distribution of the refrigerant amount may not be optimum, and thus operation efficiency may be deteriorated.
Also, in case of the heating operation, the functions of the condenser and the evaporator may be exchanged with each other. Thus, since a volume ratio for heat-exchanging between the indoor units and the outdoor unit may be changed according to the number of operational indoor units 110, the refrigerant may lean to one side.